GENERAL AR 1639382 - Caterpillar

Introduction
The problem that is identified below does not have a known permanent solution. Until a permanent solution is known, use the solution that is identified below.Problem
Reports have been received of the coolant being lost. Some customers have reported coolant being spilled out from the reservoir tank. After reviewing the reports, the coolant could not be drawn back to the radiator after the machine cooled down. Further investigation revealed that the cap and the radiator neck needed to be improved. This will hold the negative pressure and remove the air bubble in the cooling system.Solution
The radiator and cap have been redesigned to prevent the possible air leak. The facility ELC filling process has also been improved. Follow the steps below for field repair
Identify the type of radiator as shown in Illustration 2. If failures exist on the old type of 326-3876 Radiator and Hydraulic Oil Cooler Gp , order the 245-9212 Radiator Cap As . If failures exist on the new type of 347-9292 Radiator and Hydraulic Oil Cooler Gp , order the 360-9274 Radiator Cap As . The new radiator started to be used from April 2009 with the effective machine serial numbers listed in Table 1.
Table 1
Effectivity of the New Radiator    
Model    Effectivity    Adaptability    
312D     S/N:LRK387-UP     S/N:LRK1-386    
320D     S/N:A6F1077-UP     S/N:A6F1-1076    
S/N:A8F1441-UP S/N:A8F1-1440    
S/N:MGG1522-UP S/N:MGG1-1521    
S/N:FAL4793-UP S/N:FAL1-4792    
S/N:PCM130-UP S/N:PCM1-129    
S/N:BZP1388-UP S/N:BZP1-1387    
S/N:BWW112-UP S/N:BWW1-111    
S/N:BWZ4803-UP S/N:BWZ1-4802    
S/N:CYZ228-UP S/N:CYZ1-227    
S/N:JFZ4470-UP S/N:JFZ1-4469    
323D     S/N:PBE317-UP     S/N:PBE1-316    
S/N:LFL263-UP S/N:LFL1-262    
Perform the following steps before there are any field actions against the coolant return issue.
Illustration 1 g02657560
Maintain the coolant level of the reservoir between the Low mark and Full mark. Fill up the radiator to brim full
Check if there is any leak between the radiator and the reservoir.
Air venting should be performed by the following steps: Start the engine. Operate the engine without the radiator cap until the water temperature regulator opens and the coolant level stabilizes. Fill up the radiator to brim full whenever the coolant level is low.Note: If continuous air bubbles exist in the radiator, check for a combustion gas leak in the cooling system.
If problem still exists after the above steps, replace the radiator cap.
Illustration 2 g02637916
Note: The new cap and the old cap cannot be swapped for field repair.